An Experimental and Numerical Investigation of Turbulent Vortex Breakdown and Aircraft Wakes

摘要

Solutions to the steady, axisymmetric Reynolds-averaged Navier-Stokes equations have been obtained for turbulent vortex breakdown within a slightly diverging tube modeled after the experimental configuration of Sarpkaya. Solutions employing both standard and RNG based two-equation turbulence models were obtained, as were solutions obtained using a full differential Reynolds stress model. Inlet boundary conditions were derived from experimental data for the mean flow and turbulence kinetic energy as provided to the author by Sarpkaya. The differential Reynolds stress model predicted well the experimentally determined location of breakdown, whereas both two-equation models failed to even predict the occurrence of breakdown. Failure of the two-equation models is attributed to their inability to accurately account for Reynolds stress anisotropies.